USB: serial: safe_serial: fix information leak in completion handler
authorJohan Hovold <johan@kernel.org>
Mon, 6 Mar 2017 16:36:41 +0000 (17:36 +0100)
committerBen Hutchings <ben@decadent.org.uk>
Tue, 18 Jul 2017 17:38:31 +0000 (18:38 +0100)
commit 8c76d7cd520ebffc1ea9ea0850d87a224a50c7f2 upstream.

Add missing sanity check to the bulk-in completion handler to avoid an
integer underflow that could be triggered by a malicious device.

This avoids leaking up to 56 bytes from after the URB transfer buffer to
user space.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
drivers/usb/serial/safe_serial.c

Simple merge